Braking system for electric earth-boring machines



F. W. HILD BBKING SYSTEM FOR ELECTRIC EARTH BORING IACHINES m v xTN'EssEs: INvENroR u i Heder/a kmo/4 BY A'oREY oa. 21, 192s. 1,558,816

- F. W. HILD BHAKING'SYS'TEK FOR ELECTRIC EARTH BQRING IACHINES Filed July 28, 1923 2 Sheets-Shoot v2 INVENTOR TNEs Es:

m Heder/'6, PZH/7d. y

BY A

Patented Oct. 27, 1925.

FREDERIC W. HILn RRAKING SYSTEM FOR or LosfANGELIis, cALIroRNIA.

ELECTRIC EARTH-BORING ivIAcIIINns;y

yApplication filed July 28, 1923. Serial No. 654,303.

To all ywhom t fin/ay concern.'

- Be Ait known that I, Fnnnnnrc WV. HILD, a citizen of the United States, and a resident of Los Angeles, .'n the county of Los Angeles VandlState of California, have invented a new and useful lmprovement in Braking. Ma.

Systems for Electric` Earth-Boring chines, of which the following is aspeciication. y

' My invention relates to brake mechanisms, more especially to brake members associated with hoisting drums or thelike that are employed in earth boring operations; It is among the vobjects ofmy invention to provide a brake member which is semi-automatic in its function and which is operated and controlled byeither manual, gravityactuated or electro-magnetic means, which co-ordinate to perform the various functions of actuating and maintaining the brake mechanism` in its various operating positions. Y

It is a further'object .of my invention to provide a device of the above designated character which shall be of simple, compact and durable mechanical construction, which shall be efficient in its function of controlling` a hoist or requirements of earth boring mechanism or the like and which shall insure absolute safety for'the operator. y

Heretofore the brake mechanism for earth boring machinery consisted of a brake band associated with the lianges of drum which was controllable by 'a hand operated lever, and its effective capacity depended largely upon the strength and weight of the operator. Such a brake member required constant manipulation, was of limited capacity, and somewhat uncertain because the load to be braked might at times exceed the weight and leverage which the n operator could apply.

My present invention is directed to a braking device that is designed to overcome these difficulties by providing positive an reliable braking means that is mechanically controlled thereby obviating the need' o constant attention by the operator. The brake control mechanismV is arranged such manner as to make the application 'o the brake independent of the manipulation of the control lever thereby insuring safety `and certainty#ofJ operation.f

of the magnet drum 'in v accordance with the l the hoist f 13 of the drum 2 and 'The brake is adapted to be heldin its operating position bya weight which is connected by a system of links, levers and shafts to the brake band and thek weight is soconnected "as to apply the load on the brake4 independent of the forces exerted on the operating lever. Then the vbrake is released, the weight-is positioned to be effective in relieving the tensi'on from thebrake band andan velectromagnet is further provided to'hold the 'weight in this inoperative position. The linkage is provided with con-v tact-members which are arranged to operate a switch to automatically energize the coil of the linkage that will assure the most efficient use of the magnet.l The brake engagement is eected through the weight member' thereby' taking the load from the operating lever.

In the accompanying ing a part hereof and ence lcharacters designate like parts,

- Figure 1 is a side elevational view of a drum rigging such as is commonly employed in earth boring operations, e Fig. 2 is -an end elevational view thereof, Fig. 3 is a fragmentary portion of a derrick post as shown in ig. 2 with the counterweight and holding mechanism mounted thereon, and

drawings constitut- Fig. 4 s a corresponding ond elevational view thereof.l

Referringv to Figs. 1 andy 2,'the device comprises a plurality of vertical struts or supports 1 provided with a hoist drum 2 and shaft 3 which is journaled in suitable bearing brackets 4 secured to the struts 1. A brake shaft 5 is mounted on the struts 1 in alinement with the drum 2. A winch shaft 6,y jonrnaled in rsuitable bearing brackets'f, is secured to the members 1 in alinement with the drum 2 andy is provided at its outer extremities with cat heads or small drums 8. The drum shaft 3' is'provided witha sprocket g l byV a chain 10 'connected to 'af driving gear (not shown). l y Y j l.Referring to Fig. 2,! a plurality of brake bands 12 are disposed aroundthe flanges are yieldingly secure tension springs 14 that are 15 to the brake [the brake band atone end by connected by hanger straps shaftv 5.' The other endet at a predetermined position` in which like refer-v Uear 9 which is driven as a restor stop for the lever 22.

12 is connected to the brake shaft 5 by crank levers 16. A crank 17 is mounted on the shaft 5 and is connected by a link 18 to a crank 19 secured tof a stud shaftV 20 pivotally mounted on the support 1. An operating lever 22 is keyed or otherwise secured to the shaft and clevis 23, provided with a counter-weight 24,. is secured on the shaft 20 in such a manner as to cooperatively engage the lever 22.

A stop pin 25 is provided on the support A casing 28 encloses a counter-Weight 29, a switch aind. an electromagnet 31, Figs. 3- and el, at the foot of the support 1. The Weight 29 is mounted on the shaft 2() and the switch 30 and the magnet 31 are securedV to the support by an angle plate 32 andl mounting bracket 33. The Weight 29 is provided With an adjustable contact member 35 adapted to aline itself With the contact surface of the magnet 31 and a cam 36 is provided a roller member 37 pivotally mounted 1n a switch arm 38 for actuating t-he switch 30.

The opera-tion of the device is briefly as follows: The brake band 12 engages the drum flange 13 by disposing the counteriveight 29 in the position illustrated 'in Fig. 3, which is accomplished independently of the lever 22, by actuating the link 18 to operate the brake sha-ft 5 through the crank l7to dran7 up the bands 12. To release the brake tension on the drum the level' 22 is manipulated to the position 22a illustrated in Figs. 2 and 3 thereby raising the weight 29 by pivoting` it on the shatA 2O to bring the contact member 35 .in engagement with the magnet 31. Thilo traversing this arc, the cam 36 strikes the roller 37 of the switch-arm 33 which energizes the magnet 31 shortly before contact is made by the member 35. rlhis action prevents the heavy rush of current in the alternating current magnet by reducing the air gap. The hand lever then automatically returns to the positions 22 shown onv Figs. 2 and. 3 by reason of the gravity effect of counternveight 241- on clevis 23 actuating on lever 22.

The function of the brake bands is such as to free them for most of their circumference when the levers move to release the brake. The action of the springs 14 prevents sagging of the bands when the brake is released.

The arrangement of the electromagnet and the electric switch is novel in brakes of lthis type, as are the co-operating parts. The c'levis and counter-weight provided on the hand lever assures safety to the operator and4 effects-a return of the lever to the stop position when released by the operator. lf the `veig`;ht should'for any reason drop from the -qpe'lLPQSitio-n to theV closed positension means for a brake Lesser@ tion of the brakes, the hand lever would not be affected and would not move.

lt will be obvious to those skilled in the art that various modilicaticns. may be made in the details of construction Without departing from the principles herein set forth and that a brake mechanism such as l have described applicable to other uses.

l claim as my invention l. A brake mechanism comprising a surface band adapted to engage a drum, a shaft for actuating said band, an operating shaft having a han-d lever connected therewith, a balance Weight mounted thereon and a hold-ing magnet for said Weight, said brake actuatingr shaft and said operating shaft being operatively connected by a plurality of cranks and a link. y

2. A brake mechanism comprising a surface band, means for actuating said band, means for holdingv said band in its operative position and electromagnetic means for maintaining said holding means inoperative.

3.A A brake mechanism comprising gravity ban-d, manual control means for operating said tension means andi electromagnetic means for rendering said tension means inoperative.

l. A brake mechanism comprising a drum having' a plurality of brake bands mounted thereon, a shaft connected to said bands, actuating means for said shaft comprising a Weight and a hand lever, and an electric switch and a holding magnet associated With said weight and lever'.

5. A brake mechanism comprising a brake drum and a plurality of friction bands,4 means for releasing said bands from the drum and a gravity-actuated Weight for engaging said bands with the said drum.

6. A brake mechanism comprising a plurality of brake drums and friction bands, means for releasing sai-d bands from the drums, a gravity-actuated Weight for engaging said bands with said drums, electromagnetic means for holding said Weight in its inoperative position and automatic means for energizing said magnet. a

7. A brake mechanism comprising a plurality of brake drums and friction bands means for releasing said bands from the drums, a gravity-actuated Weight for enl gaging said bands with said drums, electromagnetic means for holding said Weight in its inoperative position, and automatic means for de-energizing said magnet and releasing said Weight-into operative position. I

8, A brake mechanisn'i comprising a plurality of brake drums and friction bands, means for releasing said bands from the drums, a gravity-actuated Weight for engaging said bands with said drums, electromagnetic means for holding said Weight-1.1i'

ing and maintaining tension on said band,

tension applying means.

In testimony =whereof, I have hereunto subscribed my name this 9th day of July FREDERIC W. HILD.

and means for automatically moving said hand lever out of engagement With said 10 

